deep recursion in references can cause a crash

[davidnich]

==221447== Memcheck, a memory error detector
==221447== Copyright (C) 2002-2022, and GNU GPL'd, by Julian Seward et al.
==221447== Using Valgrind-3.19.0 and LibVEX; rerun with -h for copyright info
==221447== Command: /usr/bin/qore -b /home/david/src/Qorus/git/qorus/doxygen/doxygen-api-filter.q --rest=/home/david/src/Qorus/git/qorus/build --outdir=/home/david/src/Qorus/git/qorus/build/doxygen /home/david/src/Qorus/git/qorus/Classes/QorusRestApiHandler.qc /home/david/src/Qorus/git/qorus/Classes/QorusRestApiHandlerV2.qc /home/david/src/Qorus/git/qorus/Classes/QorusRestApiHandlerV3.qc /home/david/src/Qorus/git/qorus/Classes/QorusRestApiHandlerV4.qc /home/david/src/Qorus/git/qorus/Classes/QorusRestApiHandlerV5.qc /home/david/src/Qorus/git/qorus/Classes/QorusRestApiHandlerV6.qc /home/david/src/Qorus/git/qorus/Classes/QorusRestApiHandlerV7.qc /home/david/src/Qorus/git/qorus/Classes/QorusRestApiHandlerPublic.qc /home/david/src/Qorus/git/qorus/Classes/QorusCreatorRestApiHandler.qc /home/david/src/Qorus/git/qorus/Classes/RemoteDevelopment/API/DeployRestClass.qc /home/david/src/Qorus/git/qorus/Classes/RemoteDevelopment/API/DeleteRestClass.qc /home/david/src/Qorus/git/qorus/Classes/RemoteDevelopment/API/ReleaseRestClass.qc /home/david/src/Qorus/git/qorus/Classes/RemoteDevelopment/API/TestRestClass.qc /home/david/src/Qorus/git/qorus/Classes/RemoteDevelopment/API/RemoteDevelopmentRestClass.qc /home/david/src/Qorus/git/qorus/Classes/Metrics/API/MetricsRestClass.qc
==221447== 
==221447== Stack overflow in thread #1: can't grow stack to 0x1ffe801000
==221447== 
==221447== Process terminating with default action of signal 11 (SIGSEGV): dumping core
==221447==  Access not within mapped region at address 0x1FFE801FF8
==221447== Stack overflow in thread #1: can't grow stack to 0x1ffe801000
==221447==    at 0x50151C2: std::_Rb_tree<lvalue_ref const*, lvalue_ref const*, std::_Identity<lvalue_ref const*>, std::less<lvalue_ref const*>, std::allocator<lvalue_ref const*> >::_M_get_insert_unique_pos(lvalue_ref const* const&) (stl_tree.h:2111)
==221447==  If you believe this happened as a result of a stack
==221447==  overflow in your program's main thread (unlikely but
==221447==  possible), you can try to increase the size of the
==221447==  main thread stack using the --main-stacksize= flag.
==221447==  The main thread stack size used in this run was 8388608.

#15 0x00007f92b77ef099 in ClosureVarValue::getLValue (this=0x36c4f70, lvh=..., for_remove=true) at /home/david/src/qore/git/qore/lib/Variable.cpp:1943
#16 0x00007f92b77c9e8c in VarRefNode::getLValue (this=0x3647560, lvh=..., for_remove=true) at /home/david/src/qore/git/qore/lib/VarRefNode.cpp:249
#17 0x00007f92b77e8758 in LValueHelper::doLValue (this=0x7ffc426cb4f0, n=..., for_remove=true) at /home/david/src/qore/git/qore/lib/Variable.cpp:592
#18 0x00007f92b77e8695 in LValueHelper::doLValue (this=0x7ffc426cb4f0, ref=0x30f9f20, for_remove=true)
    at /home/david/src/qore/git/qore/lib/Variable.cpp:578
#19 0x00007f92b77ef0d3 in ClosureVarValue::getLValue (this=0x36af6e0, lvh=..., for_remove=true) at /home/david/src/qore/git/qore/lib/Variable.cpp:1944
--Type <RET> for more, q to quit, c to continue without paging--
#20 0x00007f92b77c9e8c in VarRefNode::getLValue (this=0x31fee60, lvh=..., for_remove=true) at /home/david/src/qore/git/qore/lib/VarRefNode.cpp:249
#21 0x00007f92b77e8758 in LValueHelper::doLValue (this=0x7ffc426cb4f0, n=..., for_remove=true) at /home/david/src/qore/git/qore/lib/Variable.cpp:592
#22 0x00007f92b77e8695 in LValueHelper::doLValue (this=0x7ffc426cb4f0, ref=0x369c640, for_remove=true)
    at /home/david/src/qore/git/qore/lib/Variable.cpp:578
...